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Efficacy of Continuous Positive Airway Pressure in Reducing Oxidative Stress in Individuals With Sleep Apnea (SASS)

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Reena Mehra, Case Western Reserve University Identifier:
First received: January 25, 2008
Last updated: July 21, 2014
Last verified: July 2014

January 25, 2008
July 21, 2014
September 2006
July 2011   (Final data collection date for primary outcome measure)
Oxidative stress [ Time Frame: Measured between Months 2 and 3 of treatment ]
Same as current
Complete list of historical versions of study NCT00607893 on Archive Site
  • Blood pressure [ Time Frame: Measured between Months 2 and 3 of treatment ]
  • Pulse wave analysis [ Time Frame: Measured between Months 2 and 3 of treatment ]
  • Measures of inflammation [ Time Frame: Measured between Months 2 and 3 of treatment ]
  • Salivary cortisol [ Time Frame: Measured between Months 2 and 3 of treatment ]
  • Insulin resistance [ Time Frame: Measured between Months 2 and 3 of treatment ]
Same as current
Not Provided
Not Provided
Efficacy of Continuous Positive Airway Pressure in Reducing Oxidative Stress in Individuals With Sleep Apnea
Oxidative Stress in Sleep Apnea and Cardiac Disease
Sleep-disordered breathing (SDB) is a condition in which a person experiences frequent breathing pauses during sleep, also known as sleep apnea. There is evidence that the recurrent sleep arousal and associated shortage of oxygen in the body may increase risk for cardiovascular disease (CVD). It is believed that treatment with continuous positive airway pressure (CPAP) may reduce certain risk factors for heart disease, including markers of inflammation and oxidative stress. This study will evaluate the effectiveness of CPAP in reducing CVD risk factors in people with SDB.

It is estimated that 18 million Americans are affected by SDB. SDB involves repeated sleep arousal caused by breathing difficulties. These frequent sleep disruptions may cause a person to experience daytime drowsiness, impaired mental functioning, and trouble concentrating or staying alert. SDB is also associated with an increased risk of certain cardiovascular diseases, such as high blood pressure and heart disease. Researchers believe that increased oxidative stress and inflammation associated with SDB may play a role in the physiologic pathway linking SDB and CVD. However, more information on the SDB-CVD relationship is needed to be able to identify risk factors for CVD and to discover the best means of treatment. CPAP, a current treatment for SDB, acts by delivering air through a mask during sleep. CPAP helps improve overnight breathing and quality of sleep and may, in turn, decrease oxidative stress and associated CVD risks. This study will compare the effectiveness of CPAP versus placebo CPAP in reducing CVD risk factors, such as oxidative stress markers, in people with SDB.

Participation in this study will last between 2.5 and 4 months and will include four to five study visits. During the first study visit, participants will undergo a CPAP titration study, which will involve appropriate CPAP mask fitting and an overnight sleep test to determine the best CPAP pressure, as well as a lower placebo pressure, for each participant. Participants will also be provided educational information on diet, sleep, and the use of CPAP as a treatment for sleep apnea. After the titration study, participants will be asked to wear their fitted CPAP mask every night for the next 2 weeks, during which they will use the lower (placebo) pressure one week and use the higher pressure the other week. During this time, a technician will contact participants every 3 to 4 days to address any questions or problems with the CPAP equipment.

One month later, participants who were able to tolerate and use CPAP most nights will attend Visit 2. This second visit will include an overnight sleep study without wearing the CPAP mask; blood and saliva collection; cheek brushing for genetic material; tests on diabetes, artery stiffness, and circulation; body fat measurements; and questionnaires. Participants will then be randomly assigned to use either the higher pressure CPAP or the lower pressure CPAP for 8 weeks. Visit 3 will occur 1 week after beginning CPAP treatment and will include a fasting blood test. During treatment, participants will be periodically contacted by a technician to check on equipment status.

Upon completing treatment, participants will undergo repeat tests from Visit 2, except that they will wear the CPAP mask in the overnight sleep test. This fourth study visit will mark the completion of treatment for participants assigned to the lower pressure CPAP. Participants assigned to the higher pressure CPAP will be asked to use CPAP for 4 more weeks. These participants will return at the end of the 4 weeks for a final visit, which will include a repeat sleep study and other testing.

Not Provided
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Outcomes Assessor)
Primary Purpose: Treatment
  • Sleep Apnea Syndromes
  • Oxidative Stress
  • Cardiovascular Diseases
  • Device: Continuous Positive Airway Pressure (CPAP)
    Participants will use the higher pressure CPAP, as determined by an in-laboratory attended titration study, every night for 12 weeks.
  • Device: Sham CPAP
    Participants will use the lower pressure CPAP every night for 8 weeks.
  • Sham Comparator: 1
    Participants will receive sham continuous positive airway pressure for a 2 month period. Sham CPAP involves wearing a device that appears similar to a standard CPAP device, but administers a negligible pressure. Adherence will be tracked while the participant wears the device.
    Intervention: Device: Sham CPAP
  • Experimental: 2
    Participants will receive continuous positive airway pressure for a 2 month period. The optimal treatment pressure will be identified during a titration study prior to trial enrollment. Adherence will be tracked while the participant wears the device.
    Intervention: Device: Continuous Positive Airway Pressure (CPAP)

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
July 2011
July 2011   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Moderate to severe SDB (Apnea Hypopnea Index [AHI] greater than or equal to 15) diagnosed within the 2 months before study entry
  • Able to participate in more than two overnight/daytime sleep and physiologic assessments over a 2.5-month period

Exclusion Criteria:

  • Current or planned use of specific sleep apnea treatments (e.g., CPAP, oral appliance) outside of the study
  • Anticipated upper airway surgery or gastric bypass surgery in the 4 months after study completion
  • Supplemental oxygen use
  • Primary sleep disorder other than sleep apnea (e.g., periodic limb movement disorder)
  • Severe chronic insomnia or circadian rhythm disorder with less than 4 hours of sleep per night, chronic problems falling asleep within 1 hour of bedtime, or chronic problems with early morning awakenings
  • Unstable medical conditions (e.g., new onset or changing angina; heart attack or congestive heart failure exacerbation documented within the 6 months before study entry; high grade cardiac dysrhythmia/heart block; known unaddressed coronary artery disease by history, angina, stroke, or uncontrolled hypertension or diabetes mellitus; thyroid disorder; cirrhosis; a non-skin cancer diagnosed within the 2 years before study entry)
  • Inadequately treated psychiatric disorders or compromised competence
  • Daytime sleepiness with reports of sleepiness while driving or during other situations that would present a risk for the subject or public (e.g., operating heavy equipment)
  • Alcohol abuse
  • Pregnancy
  • Use of oral corticosteroids
Sexes Eligible for Study: All
20 Years to 75 Years   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
United States
K23HL079114 ( US NIH Grant/Contract Award Number )
Not Provided
Not Provided
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Reena Mehra, Case Western Reserve University
Case Western Reserve University
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Reena Mehra, MD, MS University Hospitals Cleveland Medical Center
Case Western Reserve University
July 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP